Food and Nutrition
Every day we eat food to live. Food is any substance that is consumed by animals to produce energy and aids in the body's nutrition and growth. It is the animal or plant origin that contains proteins, lipids, carbohydrates, vitamins, and minerals. These components are known as essential nutrients. The nutrients are taken by the organisms, absorbed or digested by the cells to produce energy. Food helps in maintaining the life form or stimulates body growth.
The body gets energy from the food. During the process of photosynthesis, solar energy is permanently embedded in the food. During respiration, the static energy is released in the form of heat energy or kinetic energy, which regulates all the metabolic functions of the body, such as respiration, excretion, nutrition, and other physiological functions, such as growth, movement, reproduction, etc. Therefore, every organism has to take food to live. So, the substance is consumed by the organisms to enhance the body's growth, nourishment, energy production, and utilization are called food.
Nutrition is the process by which the living organisms assimilate food and uses it for growth and replacement of tissues and keeping the body healthy and strong. In this case, animals receive nutrients from the environment and fulfill the body's energy. It also helps in preventing disease. Some essential nutrients such as glucose, mineral, salts, vitamins, etc. maintain proper nutrition of the body
Role of Good Food
Classification of Food
Food is divided into the following two types based on the function of the food in the body:
1. Body Supportive Food: Foods that help in the formation, growth, and production of energy are called body supportive foods. Important body supportive foods are carbohydrate, protein, and fat or lipid.
2. Body Maintaining Food: Foods that protect the body from infection, which are not contributing to energy production, is called body maintaining food. Significant body maintaining foods are vitamins and minerals.
Based on the maintenance of the body, food can be divided into the following three types:
1. Energy Producing Food: The primary role of these foods is to keep the body fresh and functioning by producing energy and heat. Internal activities of the body, such as breathing, cardiovascular, and other body functions, digestion, excretion, and all events in daily life, etc. require energy. In this case, the body gets energy from these types of food.
The most important energy-producing foods from which body gets energy are:
Grain-based food: rice, wheat, corn, maize, etc.
Root-based food: Potatoes, sweet potatoes, cassava, etc.
Oily or fatty foods: All kinds of oils, ghee, meat fats etc.
Sugar, and sweets, etc.
2. Body Building, Growing, and Repairing-based Foods: These diets are mainly used in the body to create or maintain body structure, enhance the body, and repair the body. These foods are derived from animal and plant sources: Eggs, milk, fish, meat, etc. while animal sources are eggs, milk, fish, meat, etc.
Food derived from plants sources: All kinds of pulses, peas, bean seeds, jackfruit seeds, nuts etc. are notable.
3. Disease Resistant food: The main role of these diets is to increase the immune system of the body, protect the body from various diseases or illnesses. Disease-resistant foods include Colored vegetables, Fruits, etc.
Basic Food Types
The primary foods are divided into the following six types:
Carbohydrates are composed of three components: carbon, hydrogen, and oxygen. In this case, the ratio of hydrogen and oxygen is 2: 1. respectively. Molecular symbol of carbohydrates: Cn(H2O)n. For example, glucose(C6H12O6), sucrose(C12H22O11), etc.
Sources: rice, wheat, corn, potatoes, oats, beets, carrots, dates, grapes, apples, Vegetables, watermelons, ripening fruits such as Mango, banana, oranges, milk and liver, etc.
Classification of Carbohydrates
Carbohydrate is divided into the following three types based on the presence of one or more units of simple sugar:
1. Monosaccharides: The sugars that are made up of only one molecule of carbohydrate, called monosaccharides-for example, glucose, fructose, and galactose.
2. Disaccharides: The sugars that makeup two molecules of carbohydrates, called disaccharides—for example, sucrose, lactose, and maltose.
3. Polysaccharides: The sugars that are made up of more than two to many molecules of carbohydrate, called polysaccharides, for example, starch, glycogen, and cellulose.
Nutritional Importance of Carbohydrates
Protein consists of carbon, hydrogen, oxygen, and nitrogen. Sulfur and phosphorus are also often present in proteins. Protein-molecules are composed of numerous amino acids. Among amino acids, the following essential nine amino acids must come from food, include:
- Tryptophan, and
Animals-based proteins are found in fish, meat, milk, eggs, and plant-based proteins such as pulses, soybeans, beans, wheat, etc. Animal-based amino acids are the first class of amino acids or proteins since they contain almost all types of essential amino acids.
Classification of Protein
Proteins can be mainly divided into the following three categories:
1. Simple Proteins
Proteins that are not attached to any other ingredient are called simple proteins. Examples: albumin, globulin, protamine, histone, gliadin, glutelin, etc.
2. Conjugated Protein
When simple proteins are linked to other non-protein substances, they are called conjugated proteins. Examples: hemoglobin, hemocyanin, phosphoprotein, lipoprotein, etc.
3. Derived Proteins
The proteins are derived through partial or complete hydrolysis from simple or conjugated proteins, known as derived protein, for example, peptone, peptide, etc.
Nutritional Roles of Protein
It is noted that the combustion of 1 gram of protein molecule produces 4.1 kcal of heat energy. An adult person needs about 100-150 grams of protein per day.
Protein deficiency Symptoms
Lipids or fats are made up of carbon, hydrogen, and oxygen. In this case, the oxygen ratio is lower than the carbohydrate, and here, hydrogen and oxygen are not present in the 2 : 1 ratio like a carbohydrate. Fat is actually an ester made up of acid and glycerol.
Lipid is insoluble in water but soluble in ether, alcohol, and chloroform. It constitutes the animal and plant cells, together with carbohydrates and proteins. It is actually an important part of living cells. Examples: Cholesterol and triglycerides.
Plant-based lipids are nuts, coconut, mustard seeds, sesame seeds, cotton seeds, etc. and animal-based pilids are butter, ghee, fats, etc.
Classification of Lipid
Lipid is generally of two types, namely:
1. Simple Lipid or Fat: Lipid that is not linked to any other substances is called simple lipid. For example, wax, fats, etc.
2. Compound Lipid: When simple lipids are associated with any other substances, then they are called compound lipid, for example, phospholipid, glycolipid, amino-lipid, etc.
Nutritional Roles of Lipid:
Vitamin is a special organic component that helps the nourishment of the body and increases the immune system. It is an essential micronutrient that requires small quantities in the body of organisms. It is important for the appropriate functioning of the body's metabolism. The organisms cannot synthesize these essential nutrients. Hence it must be supplemented through the diet from outside.
Classification of Vitamin
Vitamins are divided into two groups, according to solubility, namely:
1. Fat-Soluble Vitamins: Vitamins that are dissolved in oils or fats are called fat-soluble vitamins, for example, Vitamin A, D, E, K.
2. Water-soluble vitamins: Vitamins that are dissolved in water are called water-soluble vitamins, for example, Vitamin B-complex and Vitamin C.
Sources of Vitamins
Milk, Eggs, Fish, Meat, Animals, Oil, Butter, Vegetable Oil, Almonds, Rice, white Flour, Pea, Beans, Carrots, Palanquin, Tomatoes, Cabbage, Fruits like mango, apple, etc. are the main source of vitamins. Most of the vitamins are found in milk, eggs, spinach, tomatoes, beans, bananas, apples, etc.
The sources of vitamins A and D are cod, halibut liver, liver oil, butter, milk, eggs, carrots, cabbage, etc. Coconut, mustard oil, kernel seeds, cotton seeds, etc., contain vegetable fats and butter, ghee, fats, etc. contain animal fats.
Nutritional Roles of Vitamins: Generally, balanced food helps to provide sufficient vitamins to the body. Old-aged people (50 years and more) requires enough vitamin B12.
The Following Table Shows the Water-Soluble Vitamins, their roles and Sources
Vitamin B1 (Thiamine)
They are available in all nutritious foods in reasonable amounts: Meat, whole-grain cereals, legumes, nuts, and seeds, or breads.
It is found in leafy green vegetables, whole-grain, cereals bread, milk, and milk products, etc.
Vitamin B3 (Niacin)
It is found in animal-based food like fish, meat, and poultry. Plant-based foods such as
whole-grain, cereals, mushrooms, asparagus, various leafy vegetables,
peanut butter, etc.
It is also rich in bread.
Vitamin B5 (Pantothenic acid)
It is widespread in both plants, and animal- based foods such as cereal grains, meat, eggs, and milk, vegetables, legumes.
Vitamin B7 or H (Biotin)
It is widely found in the following foods: Meats, liver, kidney, egg yolk, cheese, yeast, leafy green vegetables, peanuts, soybeans, mushrooms, cauliflower, nuts, and nut butters.
Vitamin B6 (Pyridoxine)
Chick peas, beef liver, fish meat, banana, tofu, milk, avocados, brown rice, potato, carrots, soybeans, whole grains, spinach, hazelnuts, fortified cereal, seeds, and different fruits.
, leafy green vegetables (spinach), and seeds, Citrus fruits (orange juice), and liver, cereals, Pasta, bread,
Vitamin B12 (Cobalamin)
Dairy milk products, eggs, fish, meat, and poultry, Seafood, milk.
Vitamin C (Ascorbic acid)
Good sources of vitamin C are fruits (citrus fruits, mangoes, strawberries, papayas,, kiwifruit) and vegetables such as cabbage family, red and green peppers, tomatoes, potatoes, lettuce, blackcurrants, broccoli, brussels sprouts,etc,.
Fat-soluble vitamins are stored up in the cells of the body. If you take a balanced diet then they get enough fat-soluble vitamins. The following table shows the sources and functions of fat-soluble vitamins.
(Retinol: Animal-based; Beta-carotene: Plant-based)
It is found in both plant and animal-based foods. Animal sources are
fortified milk, cream, cheese, butter, eggs, liver, kidneys, halibut fish oil,
Plant sources are leafy, dark green vegetables, dark-orange fruits such as apricots, cantaloupe and other vegetables such as carrots, squash, winter pumpkin, sweet potatoes,etc,.
Egg yolks, liver, fatty fish such as salmon, mackerel, and tuna, fortified milk, cheese, beef liver, egg yolks, fortified cereals, and juices. You can also get vitamin D from sunlight directly through the absorption of skin.
Plant sources are leafy green vegetables such as kale, collard greens, and spinach, cauliflower and cabbage, green vegetables such as broccoli, Brussels sprouts, green leaf lettuce, romaine lettuce asparagus, and cereals;
Animal sources are meats, liver, fish, and eggs.
5. Mineral Salt
Our body also needs the most important inorganic compounds, known as sodium chloride (Nacl) or salt. It is essential for animal life but is toxic to most terrestrial plants. Salt is considered one of the basic elements which are used throughout the world in food preparation.
Besides, the body also needs other inorganic minerals that we get from the water and soil. It is absorbed by the plants and eaten by the animals. The body requires sufficient amounts of some important minerals such as calcium, which helps in growth and making the body healthy.
Iron, chromium, iodine, zinc, copper, selenium, etc are known as trace minerals because our body needs only minute quantities each day.
The following table shows the some important minerals, their roles, sources and daily requirements:
Animal sources are small shrimp, small fish, soft bones, milk, and milk products.
• 450 mg (for adults)
Animal sources are fish, meat, milk, eggs, cheese, etc,
Vegetable sources are nuts, pulses, and grains.
• 800 mg
Animal sources are fatless meats and milk (but almost all foods contain potassium)
Animal sources are meat, liver, eggs, catfish, drying fish.
Plant sources are green mango, blackberry, and , various vegetables.
• 09 mg (for adults)
Animal sources: marine fish (fresh/dried).
Plant source: marine weeds
Shellfish, Meat, Poultry, Fish, Legumes such as Chickpeas, beans, lentils, black beans, etc. Nuts and seeds, Dairy products such as milk, yogurt and cheese, Eggs, Whole grains such as Oats, brown rice, etc.
Vegetables such as Mushrooms, asparagus, and beet, spinach, etc
•11 mg (for adult men)
•8 mg (for adult women).
(for pregnant and breastfeeding women)
Water is an important ingredient in the food. Water is essential for the human body. Body composition and internal functioning cannot continue without water. 60-70% of our body weight is water. Water is important to form the muscles of every organ, nerve, teeth, bones, etc. All of the physiological processes and the formation of cells are not possible without water.
Criteria of Balanced Diet
The body needs sufficient nutrients to make energy, which is essential for keeping various systems working properly. It also helps in proper growth and maintains the body’s tissues. All these nutrients come from the food taken by the organisms. Our body needs a new supply of nutrients every day. The most important nutrients are water, carbohydrates, proteins, and fats. Besides different minerals and vitamins play an important role as micronutreints maintaining good health.
Food and nutrition make fuel providing energy to the body. Pregnant women and adult people over 50 need sufficient vitamins and minerals such as calcium, and iron as a healthy diet. In this case, fruits, vegetables, whole grains such as brown rice, wheat play as good part in our daily diet. Besides, non-fat or low-fat dairy products, lean meat, eggs, legumes, beans, seafood, soy products nuts, etc. make good nutrition, especially for the adult people.